Rajiv, Thanks!
It's 'consecutive' port-set, and thanks for your proposal for testing 'scattered' port-set. But I don't understand will the figure be different with 'scattered' port-set NAT? To my knowledge, it's something todo with app's behaviours and NAT type(EIM in our test). Would you explain if I miss something? Thanks Cheers, Xiaohong |-----Original Message----- |From: Rajiv Asati (rajiva) [mailto:[email protected]] |Sent: Wednesday, August 10, 2011 8:39 PM |To: DENG Xiaohong ESP/PEK; [email protected] |Cc: [email protected] |Subject: RE: [Softwires] Clarification of the |stateles/stateful discussion | |Xiaohong, | |Your work is very insightful. Thanks for pointing it out. | |In your experimentation, did you use 'consecutive' port-set or |'scattered' port-set or both? If just the former, then is it |possible to experiment using 'scattered' port-set? | |Cheers, |Rajiv | | |> -----Original Message----- |> From: [email protected] [mailto:xiaohong.deng@orange- |> ftgroup.com] |> Sent: Wednesday, August 10, 2011 5:35 AM |> To: [email protected]; Rajiv Asati (rajiva) |> Cc: [email protected] |> Subject: RE: [Softwires] Clarification of the stateles/stateful |> discussion |> |> |> |> |-----Original Message----- |> |From: Rémi Després [mailto:[email protected]] |> |Sent: Wednesday, August 03, 2011 4:02 PM |> |To: Rajiv Asati (rajiva) |> |Cc: [email protected] |> |Subject: Re: [Softwires] Clarification of the stateles/stateful |> |discussion |> | |> | |> |Le 3 août 2011 à 00:39, Rajiv Asati (rajiva) a écrit : |> | |> |> Satoru-san, |> |> |> |> This is an important point that most of us forget that |> |restricting to |> |> "n" ports doesn't equate to just "n" NAT sessions rather |many more |> |> than n sessions. We must add that to the 4v6 motivation |> |draft as well |> |> as to the 4v6 comparison draft. |> | |> |+1 |> |> +1. Session number are usually many more than ports number. |> |> We tested port and sessions assumptions of applications on the A+P |> NAT, which has been documented in A+P experiments draft, to |> investigate how many ports and sessions they are costing on the NAT |> mapping table dynamically from the first NAT bindings being |> established to the last one being destroyed. |> |> Some results below: |> |> Usually, apps consume some more sessions than ports, and for the P2P |> apps, sessions number could even be as a couple of times as ports |> number. |> |> For example, BitTorrent established five hundreds of sessions while |> the port consumption was under a hundred in the first minute of the |> communication, because when BitTorrent initiates a downloading, it |> first uses the same source port to connect to the different |> destinations (destination IP and port) therefore one source port |> multiplexing different sessions. Skype is another example that uses |> one source port to multiplex different sessions thereby |saving source |> port consumptions on NAT. |> |> For exact figures of ports/session number for apps, see my page: |> |> |http://opensourcev6transtechnologies.weebly.com/experiments-results.ht |> ml The session consumption comparison among the same set of |> applications is illustrated in Figure 4. |> |> Xiaohong |> |> |> | |> |RD |> | |> |> |> |>> port. There may be multiple session to different destinations |> |>> using |> |> the same |> |>> external port. The 900G figure is valid, as long as |internal hosts |> |> reuse the |> |>> same source address+port for different destinations. |> |> |> |> Cheers, |> |> Rajiv |> |> |> |> |> |>> -----Original Message----- |> |>> From: [email protected] |> |>> [mailto:[email protected]] |> |> On Behalf |> |>> Of Simon Perreault |> |>> Sent: Tuesday, August 02, 2011 9:55 AM |> |>> To: [email protected] |> |>> Subject: Re: [Softwires] Clarification of the stateles/stateful |> |> discussion |> |>> |> |>> Simon Perreault wrote, on 08/02/2011 09:24 AM: |> |>>> Satoru Matsushima wrote, on 08/01/2011 10:41 PM: |> |>>>> Thanks, a clarification has made to clear a confusion of |> |restricted |> |> port |> |>>>> set/ranges and NAT session table limitation. Even if a CPE is |> |> allocated 256 |> |>>>> ports, NAT session can be made over 900G sessions in theory. |> |> ('2^32'<Full |> |>>>> 32bits v4 address> - '2^29'<class-D/E> - '2^7'<0/8,127/8>) * |> |> 2^8<256 |> |>> ports>. |> |>>> |> |>>> This is only true for endpoint-dependent NATs, which are |> |>>> forbidden |> |> by the |> |>> BEHAVE |> |>>> RFCs (4787 and 5382). According to these RFCs, NATs MUST have |> |>>> endpoint-independent mapping behaviour. This means that each NAT |> |> session |> |>> will |> |>>> consume one external port. |> |>> |> |>> Sorry, I confused the terminology. Each NAT *binding* |will consume |> |>> one external port. There may be multiple session to different |> |>> destinations using |> |> the same |> |>> external port. The 900G figure is valid, as long as |internal hosts |> |> reuse the |> |>> same source address+port for different destinations. |> |>> |> |>> Simon |> |>> -- |> |>> DTN made easy, lean, and smart --> |http://postellation.viagenie.ca |> |>> NAT64/DNS64 open-source --> http://ecdysis.viagenie.ca |> |>> STUN/TURN server --> http://numb.viagenie.ca |> |>> _______________________________________________ |> |>> Softwires mailing list |> |>> [email protected] |> |>> https://www.ietf.org/mailman/listinfo/softwires |> |> _______________________________________________ |> |> Softwires mailing list |> |> [email protected] |> |> https://www.ietf.org/mailman/listinfo/softwires |> | |> | |> | | _______________________________________________ Softwires mailing list [email protected] https://www.ietf.org/mailman/listinfo/softwires
